1. Refractory hypoalemia in a patient with HIV infection- A Case report Dr I V Nagesh, Dr. T Murari , Dr. VK Sashindran, and Dr VA Arun Dept. of Internal Medicine AFMC , Pune
Introduction: Renal tubular acidification (RTA) defects in HIV patients have been previously reported; such defects are more common in cases of nephrotoxic antiretroviral therapy and when there is generalized tubular disease or damage.[1]. In review of literature only two cases of HIV induced distal RTA were described.
Case history: 35 yrs old male a known case of case of HIV infection on ART (ZLN) and MDR-TB on on Inj Capreomycin, Amikacin, Levofloxacin, Ethambutol, Pyrazinamide presented with diarrhea, weakness and significant weight loss of 7 days duration. There was no history joint pain, rash, hair loss, breathlessness, or decreased urine output. Clinical examination revealed BMI 16.1kg/m2, tachycardia, tachypnoea and hypotension. Rest of the general examination was normal. Systemic examination revealed pleural effusion on the right.
Treatment :Initially we managed diarrhea with fluid replacement and K+ supplementation. Intravenous HaHCO3- 50mg in 500 ml DNS x 3 days followed by Tab Sodiumbicarbonate 2 gm QID. Potassium was supplemented to keep serum K+ > 3.5meq/l for more than 4 months.
Investigations
Hb-7.8gm%, TLC: 4300/cmm, ,
Platelet count: /cmm ESR: 26mm/hr
Biochemistry:
Serum
Na+: 136 meq/l,
K+: 1.6 meq/l,
Osmolality: 302 mosm/l
ABG:
Blood pH- 7.2
PCO2–41.3 mmHg, HCO3- :9.6mEq/l,
Anion gap- 11meq/l.
Urine
Urine Na+: 129meq/l
Urinary K+: 29 meq/l
Urinary Cl- : 147 meq/l
Urine osmolarity:
Transtubular K+ gradient(TTKG) : 15
Urine pH: 6.4
Urinary CO2: 44mm of Hg
Urinary Anion gap: +3
24h urine protein: 232 mg
24h urine phosphate:299mg
Urine blood CO2 gradient : 3
Blood sugar F/PP, Urea Creatinine/ Lipid profile : Normal
CD4 count: 96cells/µl. Serum globlins: gm%
USG abdomen and kidneys: Normal
ECG- Hypokalemia
Chest radiograph : Right sided pleural effusion.
ANA, anti Ro/La /HBS Ag / Anti HCV antibodies- Neg
Serum Caeruloplasmin- 889U/L ( u/l)
Serum Gamma globulin- 1.71g/l( ),
VitB 12 levels:Normal
and bone marrow studies were normal.
Serum cortisol : Norrmal
Discussion: The relationship between HIV and RTA was first described by Laing in 2006 [2]. In our case patient Hypokalemia persisted even after correction of fluid deficit and cessation of diarrhea ,hence led to the suspicion of RTA. Investigations revealed hypokalemia with non anion gap metabolic acidosis and urine analysis revealed findings consistent with distal RTA. Distal RTA is usually associated with Fanconi’s syndrome but in our patient no features suggestive of generalized tubulopathy or features of chronic distal RTA such as rickets or nephrocalcinosis were present. HIV induced distal RTA is usually associated with hypergammaglobulinemia, but it was normal in our patient . Hence we propose that distal RTA in this patient was most probably due to HIV per se. due to the cytopathic effect of the HIV virus itself and the mechanism is by apoptosis mediated by HIV proteins.
Conclusion: The present case demonstrated the difficulty in identifying renal tubular acidosis especially in an HIV patient with multiple comorbid conditions and the importance of early recognition and treatment to avoid potential complications
References:
1. AkbarG, Ji-An Feng, Abbas N, Thiruveedi S, Geoffrey S, Teehan S, et al. HIV Infection Itself may be a Cause of Hypokalemic Distal Renal Tubular Acidosis without Hypergammaglobulinemia. Br J Med Medic Res. 2014;4(1):
2. Laing CM, Roberts R, Summers S, et al. Distal renal tubular acidosis in association with HIV infection and AIDS. Nephrol Dial Transplant 21: , 2006.